One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

This banal Parisian entranceway is not what it seems.

This army of concretions is an unexplained geological phenomenon unlike anything else in the world.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

A crumbling island fortress that seems to be covered in a field of stone crosses but is simply incomplete.

A small town hallucinates en masse - Bad bread, or CIA science project?

This church looks more like a spaceship than a house of worship.

The castle where the Marquis de Sade lived out his darkest fantasies.

Before this bridge was built people had to wait for the ferryman, an annoyance that, the story has it, gave the town its name.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

This garden houses the remains of the ancient Greek port of Marseille.

This crack in France's seaside cliffs once hid a sinister secret.

A sandstone block marks the alleged spot where the legendary writer was conceived.

Huge Russian Orthodox cemetery in danger of being converted into open public space.

Before the electric telegraph, a chain of stone towers carried messages across France.

A private garden of sculptural eccentricities.

Whether hero or rogue, his silver bullet is said to have taken down the murderous "Beast of Gevaudan."

A miniature Corsican village built out of pebbles.

700 iron sculptures crammed into a Mediterranean park.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

Live-in sculpture begun by one family in 1979.

This prehistoric figurine is the oldest known realistic depiction of a human face.

The shape of this old salt factory complex was inspired by the course of the Sun.

An unusual sand beach in the middle of a forest.